Nimzo-Indian Defense: Classical Variation, Berlin Variation, Pirc Variation

Chess is a game of strategy and calculation, starting from the very first move. When white players start by playing d4, they are aiming to control the center and put pressure on black's position. This move opens up the diagonal for the queen's bishop and prepares for further development of the pieces. As the game unfolds, white will aim to maintain control of the center, while black looks to challenge this control and find counterplay. The opening moves of a game often set the tone for the rest of the match, and d4 is a common and powerful opening move for white.

When Black plays Nf6 in response to 1. d4, they are aiming to contest White's control of the central d4 square and develop a key piece towards the center. By placing a knight on f6, Black applies pressure on the pawn on d4 and sets the stage for a number of possible responses, including attacking the pawn with moves like c5 and e5 or preparing to castle for king safety. Additionally, the knight on f6 can help support the action of Black's other pieces in the early game. In sum, Nf6 is a flexible and popular move for Black that aims to challenge White's opening strategy.

White's move c4, also known as the Queen's Pawn Opening, is aimed at establishing central control as early as possible in the game. By advancing the pawn to c4, White creates a strong pawn chain with the pawns on d4 and e5, making it difficult for Black to gain space in the center. c4 also opens the way for White's queen's bishop to develop outside the pawn chain. As a result, c4 is a flexible move that sets the stage for a range of possible responses from both sides and can lead to a wide variety of openings. The move aims to gain an advantage in terms of space, control, and piece mobility in the opening.

In the Nimzo-Indian Defense, Classical Variation, Berlin Variation, and Pirc Variation, Black often plays e6 in response to White's move c4. By playing e6, Black fortifies their pawn on d5 and prepares to develop their dark-squared bishop to attack White's pawn chain. Additionally, e6 prepares for the move d5, which is a key way for Black to challenge White's central control. This move can help Black to control the center, discourage White from advancing their pawns further, and support the development of their pieces. In sum, e6 is a common move for Black that aims to improve their position and limit White's options.

After Black plays e6 in response to 2. c4, White often responds with 3. Nc3 as a way to continue developing their pieces and assert control over the center. By placing the knight on c3, White has the option to support their pawn on d4 or capture Black's knight if it advances to b4. The move also prepares for the development of White's light-squared bishop. Nc3 is a flexible move that allows White to respond to Black's next move while maintaining pressure and keeping options open. In this opening, Nc3 is a common and sensible move that seeks to establish a strong position.

In the opening sequence of 1. d4 Nf6 2. c4 e6 3. Nc3, one of the common ways for Black to follow up is to play Bb4. By placing the bishop on b4, Black pins White's knight, which means that it cannot capture Black's pawn on e6 without giving up control over the d4 square. Bb4 also threatens to capture White's knight on c3, which would double White's pawns and potentially weaken their position. Additionally, Bb4 helps develop Black's pieces and contributes to their control over the center of the board. In sum, Bb4 is a tactical and flexible move that can create problems for White if not responded to carefully.

In the Nimzo-Indian Defense, Classical Variation, Berlin Variation, and Pirc Variation, after Black plays Bb4 in response to White's move Nc3, White often responds with Qc2. By placing the queen on c2, White supports the pawn on d4, which is now only defended by the queen. The move also prepares for the possible fianchetto of White's king's bishop. Additionally, Qc2 helps defend against any potential threats to White's pawn on b2. In sum, Qc2 is a flexible move that allows White to control the center while keeping their options open for further development. It also sets the stage for a number of possible responses from Black, such as c5 or a6, and can help White to avoid potential pitfalls in the opening.

After White plays Qc2 in response to Black's move Bb4, Black may respond with c5, as this move directly challenges White's control over the center. By playing c5, Black attacks White's pawn on d4 while gaining space and opening up lines of play for their pieces. Additionally, c5 prepares for the possible advance of Black's pawn on d5, which would further challenge White's central control. Finally, the move potentially threatens a discovered attack on White's queen if White chooses to castle kingside. In sum, c5 is a dynamic and aggressive move that seeks to put pressure on White and gain control over the center.

After Black plays c5 in response to White's Qc2, White may respond by capturing Black's pawn with dxc5. By exchanging pawns, White aims to open up the b1-h7 diagonal for their bishop and create pressure on Black's position. The move also frees White's knight on c3 to advance to d5 or e4, where it can become a potent attacking piece. Additionally, by gaining space and removing Black's pawn from the center, White is able to maintain control over the board. In sum, dxc5 is a tactical and flexible move that seeks to improve White's position while putting pressure on Black's pawn structure.

In the Nimzo-Indian Defense, Classical Variation, Berlin Variation, and Pirc Variation, after White captures Black's pawn with dxc5, Black often follows up by castling kingside with O-O. By castling, Black is able to move their king to a safer position while simultaneously connecting their rooks and preparing for potential endgame scenarios. The move also frees Black's bishop on f8 to develop and possibly support a future pawn advance. Additionally, by castling kingside, Black adds another defender to their kingside pawn structure, making it more difficult for White to stage an attack. In sum, O-O is a solid and practical move for Black that helps fortify their position and prepare for the middle game.